Valve covers mounted on internal combustion engines used with current automobiles are being made of various types of materials. Some are made from a metallic material such as aluminum, magnesium, or steel while others are made using a thermoset plastic or thermoplastic material. The valve covers made of aluminum and magnesium are manufactured using a die cast process and afterwards coated with a clear coat of paint. Those made of steel are made using a stamping process and, afterwards, are also painted. Some of the stamped steel valve covers are tri-layer formed with a plastic constrained layer for sound dampening purposes.
One problem with the valve covers made of aluminum and magnesium is that they are quite costly to manufacture. Those presently made of steel or a plastic material may not be as costly to manufacture but use gaskets which are not part of the cover and are not reusable. As a result, the gasket which may be a molded silicone, a molded silicone with a metal carrier, or an RTV (room temperature vulcanized) silicone must be discarded from and replaced onto the sealing surface of the cover if the cover is removed for maintenance purposes. The aluminum and magnesium covers use a molded silicone gasket which is applied or pressed into a molded groove and is also discarded if the cover is removed for service. In addition, those valve covers which may use isolated fastener systems for sound dampening purposes require separate rubber bushing to be inserted into the mounting holes of the cover. As should be apparent, separate bushing inserts tend to increase the time needed to assemble the cover.